Ammolite is an opal found primarily along the eastern slopes of the Rocky Mountains of North America shells of ammonites , which in turn are composed primarily of aragonite, with a microstructure inherited from the shell. It is one of few biogenic and pearl In 1981, ammolite was given official gemstone status by the World Jewellery Confederation (CIBJO), the same year commercial mining of ammolite began. It was designated the official gemstone of the City of Lethbridge , Alberta in 2007.
Ammolite is also known as aapoak (Kainah for "small, crawling stone"), gem ammonite, calcentine, and Korite. The latter is a trade name given to the gemstone by the Alberta-based mining company Korite. Marcel Charbonneau and his business partner Mike Berisoff were the first to create commercial doublets of the gem in 1967. They went on to form Ammolite Minerals Ltd.